Brake drum truing device



Aug. 20, 1935. w. H; MYERS 2,011,940

BRAKE DRUM TRUING DEVICE 'Filed Feb. 24, 1951 s Sheets-Sheet 1 43" WALTER H. MYERS NVENTORi Aug. 20, 1935. I w H, MYERS v 2,011,940

BRAKE DRUM TRUING DEVICE Filed Feb. 24, 1931 5' Sheets-Sheet 2 MININIIII izcrm/v AA 74 farm/v 3B INVENTOR.

' WALTER H; MYERS ATTORN Aug. 20, 1935; w MYERS 2,011,940

BRAK E DRUM TRUING DEVICE Filed Feb. 24, 1951 SfSheets-Sheet 3' INVENTOR.

WALTER H. MYERS 125 v ATTORNEY.

Patented Aug. 29, 1935 10 Claims.

.My inventionrelates to a new and useful brake I drum truing machine, and it relates morepan ticularly to a brake drum truing machinev of the portable type, which is adapted tobe attached I to the hub ofa wheel (the wheel having been removed from the automobile) in 'axial relation thereto.

The brake drums of' autoihobile wheels develop slight irregularities on their effective cylin- 10 drical surfaces, with the result that the brake shoe or brake band does not grip uniformly. To overcome this defect or" the braka' it is necessary to re-surface'or to't'rue up the brake drum to'-a smooth cylindrical surface-coaxial with respect to the wheel; This'truing up, or re-surfacing ofthe brake drumis efiectedgenerally by cutting or turning a suitable amount of the metal from the-eiiecti-ve brake surface, until all irregularities in said surface are removed. 20 Both stationary or lathe typeoi machines, as

well as portable type of machines have been devised-especially for truing brake drums.

ab1e brake drum truing machine 'whichis of will be sufficiently rigid tov permit 'a fairly rapid operation thereof without any:resultantgvibra tion or chatter.

' With the above 'and other objects in view, which will appear more fully from the following detailed description, my invention consists of a supporting post adapted to be adjustably fastened into the'hub of the wheel in an axial posi "tion, and adapted to support a fre-elyrotating,

35 generally radial'arrnand carrying at its upper end a stationary gear housingwithin which a worm and gear, or other suitable reducing gearing is suitably housed;said worm or otherdriving pinion being directly connected to an electric motor' mounted on top of said gear housing (through any suitable belt or other means) and said worm gear or other final driven gear being keyed directly to theireely rotatingsleeve' which surrounds the axial post and which carries the more fully hereinafter.

For the purpose of illustrating my invention, I a have "shown in the accompanying drawings formsthereof which are at present preferred by me, since the same have been foundin practice to givesatisiactory and reliable results,-although it I g I fragmentary manneri mayibe-i any-'typeiand con struction o'f 'wheel; TheJbrake: drum idsizdesigw 55 to be "un-derstood' that the various instrumen- 55 talities OfWhiCh ray-inventionconsists can be Figure 3 representsiasection om-line 3-3 of simple construction, positive inaction and which Figure variously arranged and"organized andmthat my invention is not-limited to the precise arrangement and organization of-the instrumentalities as herein shown'anddescribed.

Referring to the drawings-in which like refer- 5 ence characters indicate like parts:

Figure 1 represents a vertical elevationiaJl-wi'ew, partly in sectionjoi the brake: drum truing niavchine embodying my invention (the -wheel and brake drum being partly broken away). 7 r w I Figure 2 represents a top plan view 'of-the same (with the Wheel vand:brakefdrlim being similarly'broken away in part) Figure 1. Y i

Figure 4 represents a section on li'ne fi l of the stationary gear housing taken on1 line 4-4 of Figure 1.

Figure 5' representsaside elevation on .an enlarged'scale, of the ratchet feedmechanism.

Figure 6 represents aview of theratchet feeding mechanism, taken at 90 degreesto theyiew The object of my present invention is a port 1 i shown" in Figure 5. v I v I Figure 7 represents asection on' line A-'"A of Figure 8 represents-a section on'line' -;-B of "Figure 6, f 1' Figure 9 represents a front elevationfpartly in vertical section, of a modified. construction embodying my invention, particularly with respect to the power transmissionfrom the electric motor to thetool arm sleeve andlwith resp'ectito the vertical height adjustment of the lsup'porting post within the hub of; the wheel; a

The brake drum truing machine of thepres'erit invention maybe analyzedinto three main parts, to wit, the supporting post Hi, .WhichQ-isadapted to be secured axially in the hub l .I,Iof the. wheel ii; the generally radial too1-arm l 3 which 40 rotatably mounted upon the post I5 through the medium of the sleeve liwjournalled'upon-said ---post, and lastly, thestationary gear; housing 15 stationarily mounted upon the upper end of, the post- Wand carrying iwithinit the worm gear keyed to an upper extension of the;sleeve;-;l 4;;and 1a worm ll-enineshed withsaidworm-(gear;v l6, whichis rotatedor'driven through a pulley [8, *which' in turn is driven through thabelt Hi and 'ipulley 26, by the electric-- motor 2l,-.mounted on top of thegearzhousing l5. The automobile 3 wheel vi and brakerdrumt illustratedwparticularly ineFiguresTl-jand 2:- in a nated by the numeral 22, while the tire is designated by the numeral 23.

The supporting post In is extended through the hub ll of the wheel I2, and is axially secured to said hub and serves as the support both for the rotary tool arm l3, as well as for the stationary driving mechanism, including the gear housing 15, and the electric motor 2|.

The generally radial tool arm I3 is formed integrally with the sleeve l4, and is preferably a cast iron or cast steel member. The arm I3 is preferably tangential with respect to the sleeve l4, so that the tool point 24 carried by said tool arm l3, may be positioned in a plane in which the axis of the tool post In lies, so that the tool 24 may always be disposed in true radial relation to the axis of rotation.

The supporting post It is provided with varying diameter, concentric or coaxial portions. Thus, the upper journal portion 25 is of the greatest diameter, suihciently large to afford a.

suitable bearing surface for the rotary sleeve M of the tool arm l3. Above the portion 25, is a somewhat reduced diameter portion 25, and above it is a portion 21 of a further reduced diameter;- the upper part of the supporting post terminating in the screw threaded portion 28 which is adapted to receive the nut 29.

The rotary sleeve I4 is provided with an upper extension 30, of reduced inner and outer diameters;the inner diameter being adapted .to fit the reduced diameter post portion 25, while the outer diameter of the sleeve extension 30 being reduced suitably to project into the stationary gear housing l5 and to receive the worm gear I6 which is housed within said stationary housing I5.

The transverse annular shoulder 3| between the two difierent diameter portions 25 and 26 of the supporting post I0, serves to give vertical support to the sleeve l4 and the tool arm I3, as seen more 1 particularly in Figures 1 and 9. While not expressly shown in Figure 1 of the drawings, yet

there is such clearance between the lower end of the bearing sleeve l4 of the tool-carrying arm l3, and the upper surface of the collar or Washer 36, as to render the sleeve entirely free of the collar 36, so that there can be no contact nor any resultant binding or clamping of the rotary sleeve l4, regardless of the thrust exerted upon the col lar by means of the. clamping nut 31, and the entire vertical support of the sleeve I4 and tool-carrying arm [3 is derived through the shoulder 31 on thepost and the corresponding offset or shoulder in the upper part of the sleeve I4, as illustrated in Figures 1 and 9.

' Below the journal portion 25 of the supporting post III, the diameter of the supporting post is successively reduced, along the portions 32, 33

and 34, resulting in corresponding annular transthe shoulder 35, that the axial force of the clamping nut 31 is exerted. Thus, upon the reduced diameter portion 33 of the supporting post ii], one or more spacing or take-up washers are detachably mounted, of suitable aggregate thickness to position the tool arm l3 at the appropriate height corresponding to the particular brake drum in relation to the hub of the wheel. Below ,the spacer, take-up or adjustment washer or washers 38, the upper conical centering Washer bolts 5 I 39 is provided, the conical surface of which is adapted to project into the bore 45 of the hub H of the wheel and to rest against the annular edge 4! of said bore, thereby to center the supporting post it. On the lowermost portion 34 of the supporting post Hi, the lower conical centering washer 52 is detachably mounmd, and below it is the clamping nut 31, threaded onto the lowermost threaded terminal portion 43 of the post H3.

The lower conical centering washer 45 projects into the lower end of the bore 45 of the hub of the wheel, and seats against the lower annular edge 44 of the bore of the hub, thereby further to center the post l0.

Thus, by clamping the supporting post it to the hub of the wheel, in the manner indicated in Figure 1, not only is the supporting post it rigidly and firmly secured to the hub of the wheel, but it is at the same time centered in true axial relation thereto.

The stationary gear housing [5, mounted stationarily and rigidly on the top of the supporting post It], is preferably formed of the lower half 45 and the upper half 45, the latter being secured to the post H! by means of the nut 29 and any other suitable keying means. The lower gear housing member 45 depends from the upper gear housing member 45, and is secured thereto by a suitable number of screws 5?, indicated more particularly in Figure 2."

The lower gear housing member '45 is provided with a central opening 48, through which the sleeve extension 30-p-rojects into the interior of the gear housing. A felt wash-er 49 is provided in the somewhat enlarged lower portion of the hole 40 in the lower housing member d5;-said felt washer" serving to minimize the leakage of lubricant from within the gear housing through the central opening 43.

The worm gear I6 is keyed or otherwise fixedly secured, to the sleeve extension 35.

In the lower housing member the Worm H is mounted, in mesh with the worm gear i6; one end of the worm shaft 55 having its free end extending exteriorly of the gear housing and car rying the pulley l8. 7

Upon the top of the gear housing l5 the electric motor. 2| is suitably mounted and secured by The electric driving motor 2| may be of any suitable type or size sufiiicent to provide the necessary power. The motor shaft 52 carries the pulley 20 in alignment with the worm shaft pulley l8, and thebelt l9 extending over said two pulleys l8 and 20, serves operatively to connect the same. By this means the rotation of the r motor shaft 52 is transmitted to the worm I! and the rotary motion of the latter is in turn transmitted at a right angle to the worm gear E5 and the sleeve i4, thereby causing said sleeve M and the tool arm l3 to revolve about an axis at a right angle to the axis of rotation of the motor and worm shaft 55, and also at a speed suitably less than the speed of rotation of the motor.

The tool arm I3 is provided on its leading face (with reference to the direction of rotation indicated by the arrow 54) with a pair of spaced parallel dovetailed guides 55 and the central channel 55 therebetween. The dovetailed guides 55 are adapted to receive and slidably support the longitudinal or radial tool carriage 51, while the longitudinal channel 55 is adapted to accommodate the longitudinal carriage feed or adjustment screw 58;said feed screw 58 having its outer end rotatably anchored in the end block 59 which is secured tothe free end of the tool arm l3.

7t: Thelongitudinal carriage filis provided 'with a :1f;cvvheri-rby::the-longitudinal carriage 5? may be moved inwardly or outwardlyin a radial direction;:thereby to set the cutter 2:2 to thedesired" gage the same in the opposite 'd'i'rection rAny asuitablei. helical compression'spring 88i-may be provided for resiliently urging the plunger or detent '85 in the'direction of the toothed'per-iphcry of the .ratchet wheel 8'2, while a" suitable exterior thumb knob '89 maybe provided on the exteriorly projecting/portion of thep'lungerstem 10?.5diametrical-dimension.' A suitably graduated collar 63 may also beprovided on the feed screw t 358, for the purposeof calibrating the longitudi- 1 nal or radial adjustingmovement or feed move--* 1.1 'ment'of thelongitudinal carriage 51 in relation to 1,5. the rotation of the feed screw 53.

I The longitudinal tool carriage 51 is in ttun pro-" tailed' guides 64, upon which is slidably mounted the-vertical or transverse'tool carriage 65. Inter- Q mediate the pair of spaced parallel dovetailed .fguides' 64 is -a channel 66, which accommodatesthe vertical feed screw 61. The feed screw 6? is in threaded engagement'with a feed nut which automatically'to define the limit of upward ver- 'tical travel of the vertical carriage 55. The vertical feed screw fill is suitably journalled at its:

" upper end in the terminal block ii. Immediately above the bareor threadless portion l oi the deed screw 67, aspiral gear i2 is provided, through "whichthefeed screw'd'l is rotated. Above the tool arm l3, and extending parallel thereto inf operative alignment with the spiral gear 12, a

feed-shaft 13 is provided, with its inner end M "ment by means of a pair of suitable collars Ti and I8.

'nalykeyway 19;: The feed shaft '13 extends through corresponding'openings in a pair of lugs A spiral gear BI is slidably mounted upon. the

' tive' rotation with the respect to the shaft 713, by meansofa key carried by the spiral gear 8! and slidable in the key-way l9. The spiral gear 8! is" disposed between the pair of lugs 88, which serve to-retainsaid spiral gear constantly in mesh with ing movement of the vertical carriage 65.

The'periodic, intermittent rotary movement of the feed shaft '73 is effected through the feed Figures 4 to? inclusive. Thus a ratchet wheel 82 as the paper pin 83 extending through the hub *'oi the ratchet gear 82 and through the shaft '53,

75 described-more irr-detail hereinafter.

vided with a pair'of spaced parallel vertical doveis anchored to the vertical carriage SS-byan journalled-in'a suitable bearing opening F5 in the body of the sleeve l4 and with theyouter end it 1 thereofjournalled in the terminal block 59 and rotatably anchored therein against axial move-' The reed shaft 73 is provided with a longitudi- 80 forming part; of the longitudinal carriage 5?.

-- 'feed shaft i3 and keyed thereto against relal' qt 'atchet mechanisrn illustrated particularly in,

--is' suitably afiixed to the feed shaft l3, near the inner end M thereof, by any suitable means such "and' surrounding said ratchet wheel or ratchet "gear 82, and freely jou'rnalled on the feed shaft 13 a pawl housing 8% is provided, adapted to be "oscillated to and fro, within suitable limiting angles, by a lever ahd'link mechanism, to be 1 Thus the pawl housing 84 hasslidablymbunted within it aspring-pressed pawl, 'detentorplunger 85, having its operative end 86. shapedicorrespending to the shape of: thertee'th 81 of the ratchet gear 82, so that when theplunger,-'detent orpawl' 85 is:resilientlysurgedinto contactwith the toothed periphery of theratchet ge'ar or periphery fin one5direction, butlwill not-so en- 98," for rna'nuallyt withdrawing the plunger or detent 85 from operative relation to the toothed periphery of the ratchet wheel 82. Airetainer pin 9i is extended through the stern an of the detent ii5,land a corresponding slot 92 is'provided in the housing 8 for receiving the pin 9|.

Whenit is desir'edto retain the detent 85 out of operative engagementwith the toothed periph;

cry of the ratchet gear 82, the .saJrne'is'withdrawn by means of the thumb-knob 39 and rotated until theretainer pin ill-extends transversely of the slot 92;-permitting said retainerpin "-91 to rest upon the terminal'surface'93 of the housing 861 When the detent'85 is thus placed -in an inoperative position, the feed shaft 'lil maybe'operated' independently or the automatic ratchet feed mechanism, by means'of'a manual' handle or nwrench applied to theouter squarershahk terininal portion 94 of the said feed shaft 13. I The intermittent angular/oscillation of the detent or pawlhousiiig'ild is effected by mearis of the pivoted arm or leversti'which'is'pivbted to the sleeve H3 by means of the 'pivot 'scrw'ilfi;

the link 91, which is piv'ota-lly securedat one end fthe'iree endof thefleve'r 95 by means of the pivot screw 98 and which is pivotally secured at itsother end to the detenthousin'g 84 by means of the pivot screw 99,'and the abutment ifill which is'fixedly secured to the stationary gear housing iii, shown particularlyin Figure 1.

Tl'iefi ed abutment lfidisin "operative alignment with the verticalcontact surface iii! of the pivotal lever or ar'mBE, so that as the sleeve 84 and the'toolarrn i3 revolve about the stationary supporting post i@,*'a'nd beneath the stationary gear housing iii, the contact surface IBI of the 'lev'e'rtb will ehcounter the stationary or fixed abutment Hit? and will bedepressed or deflected therebyinthe direction of the arrow lil2 (l 'igi-'- ure l).- This d'efiectio'n'of the lever Qfijwitheach revolution of the sleeve and tool arm i and it respectively, causes" a 'correspondi-n'g periodic deflection or angular oscillation er the .detent housing 8 and hence of the 'detent fidr 'Any suitablespring' member (not shown) Lisused for [returning the leverit! to its 'iriitiaimposition,

after each deflection by the 'rnernbe'r lflllgirr the conventional manner in which 'iatchetpawlsare customarily returned by spring. Ii theede t'ent S5 is operative relation to theto-othed periphery of the ratchet wheelor ratchet gear 82,-shown in Figures 4, 5,-6,"and 'Z, the periodic-deflection or oscillation thus produced will cause acorrespending intermittent rotatio'n'of the feed shaft lit in thesame direction. Through thesiairal gears 85 and '52, this periodic and'inter'mittent or the=vertica1 carriage 652 By this rneans the wheel 32, it will operatively engage said toothed until either the operator stops the machine after the tool 24 has run over the entire brake surface .or. until the feed nut which is operated by the verbrake drumtowards the outer free edge I03 thereof. By thus feeding the tool towards the free edge I03 of the brake drum 22, and by providing a suitable threadless portion I0 upon the vertical feed screw 61, all danger of the tool 24 overrunning or cutting into portions of the brake drum other than the braking surface, is entirely eliminated. Thus the tool isstarted at the point I94, and is fed upward. It the tool 24 runs off the brake drum edge I03, and continues to be moved upwardly by the continued operation of the machine, no harm can be done either to the brake being trued, or to the machine, since the tool 24 merely runs off the free edge I03 of the brake drum and the vertical carriage 65 ceases to move upwardly when the feed nut runs onto the blank or threadless portion 10 of the feed screw 51. i

In order to vary the rate of movement of the vertical carriage 65, a latch member I85 is pivotally secured to the portion I06 of the sleeve I4, by means of the pivot pin Hi1. A stop pin or abutment I88 is affixed to the detent housing 84, in operative alignment with the latch I05. When the latch I 95 is in the inoperative position shown particularly in Figure 7, the detent housing 84 is afforded its maximum freedom of angular oscillation. In this condition, the oscillation will cause the detent 85 to transverse three teeth of the toothed ratchet wheel 82, thereby causing the tool to be fed at a corresponding rate to provide a coarse cut. When the latch I is defiected about its pivot I81 in the direction of the arrow I09, the notched surface III) of said latch I05 is placed into operative alignment with the pin or abutment Hi8 carried by the detent housing 84. This engagement causes the detent housing 84 to be retained in a partially deflected or a predeflected condition, so that when the stationary abutment I i-i3 engages the contact surface I III of the lever 95, it will deflect said lever 95 and hence will oscillate the detent housing 84 only one-third ofits normal oscillation, so that the detent 85 will traverse the distance of merely one tooth. This, produces the fine feed which may be required for finishing the brake drum surface.

The vertical carriage 65 carries near its lower end any suitable tool post II I, including the clamping ring H2 and the nut H3. The corresponding lower portion of the vertical carriage 65 is in turn provided with a pair of oppositely inclined channels or'slots I I4, adapted to receive and seat the tool 24, at opposite inclinations, so as to position said tool for turning the internal and external surfaces respectively of a brake drum; depending on whether the brake drum surface is external or internal.

In order to insure against relative rotation between the collar 35 and the take-up or adjustment washers 38, and the conical centering washer or member 39, a dowel-pin [I5 is providedin the base of the conical centering member 39, and a corresponding hole H5 in the opposed face of the spacing washerv 38. The opposite face of the tool 24 carried by the vertical carriage. 65 is gradually moved or fed in an upward direction,

adjustment washer 38 is inturn provided with a corresponding dowel-pin II'I, which fits into a corresponding hole in the .collar 36; By this means, the successive washers may be interlocked against relative rotation, thereby further insuring against the rotation of the centering post or supporting post ID with respect to the hub II- of the wheel I2..

In actual operation of the machine of my present invention, the automobile wheel I2, including thetire 23 if desired, is monnte-d upon any suit- I able supportand the machine then attached to the hub of the wheel as indicated particularly in Figure 1. The tool 24 is then adjusted to the desired diameter by means of the longitudinal feed screw 58, and the tool started from inside, that is part of the innermost from the effective brake surface. When the tool 24 runs off the brake surface, the operator may stop the machine and remove the same from the wheel. several successive cuts may be taken to acquire the desired effect.

In the modification of my invention shown in Figure 9, the post If instead of being provided with a series of take-up or adjustment washers 38, of varying axial thicknesses, for obtaining the desired vertical adjustment of the entire machine with respect to the brake drum, is instead provided with an accurately turned screw thread I29, which is preferably a square thread and upon this square thread 20, a single screwthreaded adjustment collar IZI is threadedly mounted. The exterior periphery of the adjustment collar I2I is preferably knurled so as to facilitate its manual manipulation or turning. The

threaded end I25 of the centering and supporting post In with a left-handed screw thread, or a screw thread opposed to the square screw thread I28, so that the two screw threads .will work in opposition to each other, as indicated particularly in Figure 9. The lock nut I24 is likewise preferably knurled to facilitate manual handling.

In this modified embodiment of my invention, the lower portion I26 of the centering post lll is extended through the hub of the wheel in a manner similar to that shown in Figure l, and the adjustment nut IEI is then turned up or down until the desired vertical level or height is obtained. Thereafter, the lock nut I 24 is tightened up and the machine is so arranged that the torque exerted upon the centering and supporting post I!) by the cutting tool, will tend to tighten the screw threads, while an opposite torque, (which may be exerted manually when demounting the machine) will loosen the screw threads. By this means, a quickeradjustment is obtainable with respect to the hub of the wheel.

In this modified embodiment of my invention also, the longitudinal carriage feed or adjustment screw 58 is extended tangentially through the casting which comprises the sleeve land the tool arm I3, and to the end of the longitudinal feed screw 58 thus extended through, a knurled knob I2! is secured, whereby the feed screw 58v If desired,

aoiige os-n may be; operated manually to secure the desired radial or longitudinal adjustment ofthe tool-1 without manipulation at the outer end of the screw; as in-the modification shown in Figure 1.

Thusyby this means, the rotation of the screw 58 may be effected from a point closeto the center'of rotation rather than a point at a-confication illustrated particularly in Figure l. Theadvantages of this modification are primarily: the elimination of the belt drive it. Thus, in this modification of my inventionan internal. ring gear IE9 is providedwithin the stationary gear housing 55, carried by any suitable annular ring gear supporting housing or memberJBEL-m which; iskeyed to the upper extensiontt oi the a sleeve: i l-inimuch the same manner as the worm gear its isikeyed to said upper extension so in the modification shown in Figure 1. A driving pinion, L3,! is in operative mesh with the internal ring gear-5 29 and is adapted to drive the same.

. carriage; in; timedrelationi to ,the rotary; :motion i of said tool arm, andpmeans: extending;a1ong said and henceathe sleeve I l and tool arm l3; The driving pinion 13! may be aifixed or keyed diiiectly to the vertical motor shaft, or it maybe afiixed .or keyed toa reduced speed spindle 32,v of anyjsuitable reduction gear mechanism I33 intermediate the reduced speed spindle I32 and ,.adapted ,.'for attachment to the hub of: the wheel the motor 128. Thus, dependingentirely on the speedo-f the motor and the desired speed of rotationQorIthe arm is and the ratio;v betweenthe driving pinion l3! andsthe driven gear lZQ the drivingfpinion l3i may bedirectlyupon the shait of the motor or it maybecarried upon'the reducedspeed-spindle ofv any suitable or convene tionalsgeanreduction box, the details of which are not shown in the drawings. Thus,:if desired; a motor l2}! having areduction-gear'box133 permanentlybuilt onto one end thereof, may be used themannershown in Figure 9 by mounting v said motor I 28 vertically upon a suitable supporting or spacer ,frame, i;3 l..The supporting or spacerrframe i 34 may ,bein-the form of-acylin drical ortubularmember, the lower end oi'which rests ,upon andissecured: to the stationary gearv housing I5, and tothe upper end of: Which-is-secured themotor frame by means .of the screws I35. =-The stationary gear housing i5 maybe gen-1'; v v parting a feedingjmotion to said tool carnage 1n timed relation to the rotary motion of said tool 55 arm, and a ratchet "mechanism," including 'a ratchet shaft-extendingalongthe tool arm and operatively -connected to said screw threa dedv H means and a ratchet-wheel carried by saidratchet shaft neary-the inner end thereofyanda detenti'imahdislocked by means of. a bolt'or screw' l 39. x s; 1

I am aware thatrmy invention may be embodied in other-specific forms without departing from the spirit or essentialattributes thereof, andYI there-1 ,fore ldesire the present embodiments to be con-:

sidered in *all respects as illustrative and. not reclaims rather than to the "foregoing descriptionto indicate-"the scope'of the invention.

:25 Havingvthus described-my invention, what-'I- secured to. the hubofthe wheelin axial alignment and supporting \post adapted: to; be detachably The stationary, gear hous- 51.;

=tering- 'post', a stationary housing s'tationaril ,helfibyfclamlsfas' newvand desiriezto secureiby it;

LetterswPatent-is:aa

l. A portableybrakeudrum' truingwmachine adapted for attachmenttothe hub'of;;the wheel and "supporting post, :adapted; :to; be: detachably.

therewith and in rigidand.nonerotating rela-;- tionstheret za ,-tool carrying; sleeve and .armoroe trio motor to bedriven thereby, for imparting a; reduced speed.rotarymotionto, saidgear, sleeve:

i and tool qarm; agcarriage ,sli'dably mounted: upon} saidstcol arm-for longitudinal movement with respect; thereto; 2%; transverse; carriage; slidably 1 mounted .upon; said longitudinal lcarriageg andsa ,adapted'toisupport a;tool in operativegrelation to I saidbrake'drum: andadapted for a tool-feedingm :movement; with -respect to said tool arm" and 1:

transversely thereof; screw-threaded;meansy'for :1; imparting"a ,feeding I'IlOtlQIlifltO. said transversetool 1 arm. for automatically actuating gsaid screw-1 c. threaded transverse carriage feeding, means,1 as a.,.,

. ,,result ,of {the rotation-of the tool arm;,- 11: I

2. A. portable brake=drum' truing :machinerin carrying the brake drum,- including 1 a -,center ingf.

secured to-the hub otthe wheel inaxial alignment therewithandin rigid and non-rotatingirelation thereto; a .tool 'ca-rrying qsleeve andiarm rotatably i s mounted; upon ,;said supporting and Y centering post, a stationary: housing, stationarily mounted; 1- on the top of,said supporting-andcentering post, an electric motor carried by said housing-, a gear affixed tmsaidsleeves means in-mesh withsaid=l gearl'and housedrwithin-said housing,. and'opera 45 tively connected -withsaid.; electric motor to be I driven. -.thereby,: for imparting a reduced, speed:

rotary .motionlito said gear, sleeve and tool arm/1s a tool carriage carried by said itoolnarm, adapted brake drum and adapted for a tool-feedingmove- 'ment. with respect, to, said tool arm and ,tr-ansverselythereof, screw-threadedgmeans for jimoperated 'by a stationary abutment carried-by i" the centering and supporting'post, for imparting .portingpostlt by means of a suitable key 138 :l

supporting post: adapted to be detachably----* securedto-the hub of the wheel in axial alignment therewith and in rigid-and hon-rotating-relation; thereto, a tool= carryingsleeve and-arm ro strictive, referencebeinghad to the appendedtatably mounted upon' said-= supporting and cen carrying; the brakedrum-,1including a centering :5

jto supporta tool in'l'operativerelationto saidLfiD mesh with said gear and housed'within'said housing, and operatively connected with said electric motor to be driven thereby, for imparting a re- 'duced speed rotary motion to said gear, sleeve and tool arm, a carriage slidably mounted upon said toolarm for longitudinal movement with respect thereto, a transverse carriage slidably mounted upon said longitudinal carriage and adapted to support a tool in operative relation to said brake drum and adapted for a tool-feeding movement with respect to said tool arm and transversely thereof; screw-threaded -means for imparting a feeding motion to said transverse carriage in timed relation to the rotary motion of said tool arm, and means for automatically limiting-the travel of said transverse carriage without the necessity of stopping the machine.

i i 4. A .portable brakedrum truing machine adapted for attachment to the hub of the wheel carrying the brake drum, including a centering and supporting post adapted to be detachably secured to the hub of the wheel in axial alignment therewith and in rigid and non-rotating relation thereto, a tool carrying sleeve and arm rotatably mounted upon said supporting andcentering post, a stationary housing stationarily mounted on the top of said supporting and centering post, an electric motor carried by said housing, a gear affixed to said sleeve, means in mesh with said gear and housed Within said housing, and operatively connected with said electric motor to be driven thereby, for imparting a reduced speed rotary motion to said gear, sleeve and tool arm, a' tool carried by said tool arm, means for positioning said tool at anydesired radial distance from the axis of the supporting post, and the axis of rotation of the tool carrying sleeve and arm, within the radial limits of the machine, means for feeding the tool in a direction generally parallel to said axis of rotation, and rotary means extending along said-tool arm and having an operative connection with said stationary housing for automatically actuating said axial tool feeding means in all radial settings of the tool,-as a result of the rotation of the tool arm.

5. A portable brake drum truing machine adapted for attachment to the hub of the wheel ,carrying the brake drum, including a centering and supporting post adapted to be detachably secured to the hub of thewheel in axial alignment therewith and in rigid and non-rotating relation thereto, a tool carrying sleeve and arm rotatably rnounted upon said supporting and centering post, a stationary housing stationarily mounted on the top of said supporting and centering post, an electric motor carried by said housing, a gear afilxed to said sleeve, means in mesh with said (gear and housed within said housing, and operatively connected with said electric motor to be driven thereby, for imparting a reduced speed rotary motion to said gear, sleeve and tool arm, a tool carriage carried by said tool arm, adapted to support a tool in operative relation to said brake drum andadapted for a tool-feeding movement with respect .to said tool arm and transversely thereof, means for positioningsaid tool carriage at any desired radial distance from the axis of the supporting post and the axis of rotation of, the tool carrying sleeve and arm, within the radial limits of the machine, and rotary means extending. along said tool arm and having an operative connection with; said stationary housing for auto smatically feedingsaid tool carriage transversely housing, agear afiixed to said sleeve, means in of the tool arm as a result of the rotation of the latter. 5

6. A portable brake drum truing machine adaptedfor attachment to the hub of the wheel carrying the brakedrum, including a centering and supporting post adapted to be detachably secured to the hub of the wheel in axial alignment therewith and in rigid and non-rotating relation thereto, a tool carrying sleeve and arm rotatably mounted upon said supporting and centering post, a stationary housing stationarily mounted on the top of said supporting and centering post, an electric motor carried by said housing, a gear ai fixed to said sleeve, means in mesh with said gear and housed within said housing, and operatively connected with said electric motor to be driven thereby, for imparting a reduced speed rotary motion to said gear, sleeve and tool arm, a tool carriage carried by said tool arm, adapted to support a tool in operative relation to said brake drum and adapted for a tool-feeding movement with respect to said tool arm and transversely thereof;

screw threaded means for imparting a feeding motion to said tool carriage in timed relation to the rotary motion of said tool arm, and rotary means extending along said tool arm and having an operative connectionwith said stationary housing for automatically actuating said screwthreaded means as a result of the rotation of the tool arm.

'7. A portable brake drum truing machine adapted for attachment to, the hub of the wheel carrying the brake drum, including a centering and supporting post adapted to be detachably secured to the hub of the wheel in axial alignment therewith and in rigid and non-rotating relation thereto, a tool carrying sleeve and arm rotatably mounted upon said supporting and centering post, a stationary housing stationarily mounted on the top of said supporting and centering post, an electric motor carried by said housing, a gear affixed to said sleeve, means in mesh with said gear and housed within said housing, and operatively connected with said-electric motor to be driven thereby, for imparting a reduced speed' rotary motion to said gear, sleeve and tool arm, a carriage slidably mounted upon said tool arm for longitudinal movement with respect thereto, a

transverse carriage slidably mounted upon said longitudinal carriage and adapted to support a tool in operative relation to said brake drum and adapted for a tool-feeding movement with respect to said tool arm and transversely thereof, and rotary meansextending along said tool arm and having 'an operative connection with said stationary housing for automatically feeding said transverse carriage in a direction transversely of I the tool arm as a result of the rotation of the latter.

8. A centering device for brake drum truing machines, including a centering post adapted to .beextended through the hub of a wheel and to therewith, and tapering centering meanssurrounding said centering post, and associated with each of said screw-threaded means, and disposed intermediate the two screw-threaded means.

9. A centering device for brake drum truing machines, including a centering post adapted to be extended through the hub of a wheel and to be detachably aflixed thereto and in stationary relation thereto, a driven tool-carrying arm rotatably mounted upon said centering post, and having a tool adapted for turning the brake drum of the wheel through thehub of which the centering post is extended, said Centering post having a screw-threaded terminal portion and threaded locking means threadedly associated therewith;-the direction of the thread of said threaded terminal portion and 'said threaded means associated therewith being such as to cause said screw-threaded means to be moved towards the opposite end of the centering post when rotated in the same direction as the rotation of the tool-carrying arm.

10. A portable brake drum truing machine adapted for attachment to the hub of the wheel carrying the brake drum, including a centering and supporting post adapted to be detachably secured to the hub of the wheel in axial alignment therewith and in rigid and non-rotating relation thereto, a tool-carrying sleeve and arm rotatably mounted upon said supporting and centering post, a support stationarily mounted on the top of said supporting and centering post, an electric motor carried by said support, a gear affixed to said sleeve, means in mesh with said gear and carried on said support, and operatively connected with said electric motor to be driven thereby, for imparting a reduced speed rotary motion to said gear, sleeve and tool arm, a tool carried by said tool arm, means for positioning said tool at any desired radial distance from the axis of the supporting post, and the axis of rotation of the toolcarrying sleeve and arm, within the radial limits oi'the machine, means for feeding the tool in a direction generally parallel to said axis of rotation, and rotary means extending along said tool arm and having an operative connection with said stationary support for automatically actuating said axial tool feeding means in allradial settings of the tool, as a result of the rotation of the tool 9 arm.

WALTER H. MYERS. 

